The invention concerns a water pump, in particular for fountains or water display devices as well as garden ponds, comprising a housing with a pump housing part provided with an intake opening and an outlet opening, in which housing part an impeller with a shaft is arranged rotatably, and further comprising a motor housing part, in which an electric motor is received. The invention also relates to well as a water display device or fountain with a water pump and with several water jets.
Conventional water pumps for garden ponds and fountains are in practice externally controlled when the type and height of the water jet or generally start and stop of the pump are to be controlled. In order to achieve in fountains, primarily in multi-jet fountains, special water effects, in conventional pumps the control of the water quantity for each water outlet is realized by electric control valves. In this connection, a single large pump supplies the water into a distribution system in which individual control valves correlated with the downstream water jets are activated by an external control. These systems react very slowly and can be controlled only imprecisely. Moreover, the electric control valves represent a high cost factor. Also, the complex wiring, piping and control cause high system costs. Moreover, the running costs are high because the pump must always operate under full load. Alternatively, asynchronous pumps can be considered that are controlled by means of phase angle control. These controls are however expensive, have a slow response, and are difficult to control.